int main()
{
int err;
pthread_t tid;
if ((err = mypthread_rwlock_rdlock(&rwlock)) != 0) { /* parent read locks entire file */
fprintf(stderr, "mypthread_rwlock_rdlock error: %s\n", strerror(err));
exit(1);
}
printf("%s: parent has read lock\n", gf_time());
if ((err = pthread_create(&tid, NULL, child_thread, NULL)) != 0) {
fprintf(stderr, "pthread_create error: %s\n", strerror(err));
exit(1);
}
sleep(4);
if ((err = mypthread_rwlock_unlock(&rwlock)) != 0) {
fprintf(stderr, "mypthread_rwlock_unlock error: %s\n", strerror(err));
exit(1);
}
printf("%s: parent releases read lock\n", gf_time());
if ((err = pthread_join(tid, NULL)) != 0) {
fprintf(stderr, "pthread_join error: %s\n", strerror(err));
exit(1);
}
exit(0);
}
int
main(int argc, char **argv)
{
int fd;
pid_t childpid;
if ((fd = open("test1.data", O_RDWR | O_CREAT, (mode_t) FILE_MODE)) == -1) {
fprintf(stderr, "open error for %s: %s\n", "test1.data", strerror(errno));
exit(1);
}
if (read_lock(fd, 0, SEEK_SET, 0) == -1) { /* parent read locks entire file */
perror("read_lock error");
exit(1);
}
printf("%s: parent has read lock\n", gf_time());
if ((childpid = fork()) == -1) {
perror("fork error");
exit(1);
}
if (childpid == 0) {
/* 4child */
if (read_lock(fd, 0, SEEK_SET, 0) == -1) { /* this should work */
perror("read_lock error");
exit(1);
}
printf("%s: child has read lock\n", gf_time());
sleep(2);
if (un_lock(fd, 0, SEEK_SET, 0) == -1) {
perror("un_lock error");
exit(1);
}
printf("%s: child releases read lock\n", gf_time());
if (read_lock(fd, 0, SEEK_SET, 0) == -1) { /* this should work */
perror("read_lock error");
exit(1);
}
printf("%s: child has read lock\n", gf_time());
sleep(2);
exit(0);
}
/* parent */
sleep(4);
if (un_lock(fd, 0, SEEK_SET, 0) == -1) {
perror("un_lock error");
exit(1);
}
printf("%s: parent releases read lock\n", gf_time());
exit(0);
}
void *thread1(void *arg)
{
sleep(1);
printf("%s: first child tries to obtain write lock\n", gf_time());
Pthread_rwlock_wrlock(&rwlock); /* this should block */
printf("%s: first child obtains write lock\n", gf_time());
sleep(2);
Pthread_rwlock_unlock(&rwlock);
printf("%s: first child releases write lock\n", gf_time());
return NULL;
}
void *thread2(void *arg)
{
/* 4second child */
sleep(3);
printf("%s: second child tries to obtain read lock\n", gf_time());
Pthread_rwlock_rdlock(&rwlock);
printf("%s: second child obtains read lock\n", gf_time());
sleep(4);
Pthread_rwlock_unlock(&rwlock);
printf("%s: second child releases read lock\n", gf_time());
return NULL;
}
void *thread1(void *arg)
{
int err;
sleep(1);
printf("%s: first child tries to obtain write lock\n", gf_time());
if ((err = pthread_rwlock_wrlock(&rwlock)) != 0) { /* this should block */
fprintf(stderr, "pthread_rwlock_wrlock error: %s\n", strerror(err));
exit(1);
}
printf("%s: first child obtains write lock\n", gf_time());
sleep(2);
if ((err = pthread_rwlock_unlock(&rwlock)) != 0) {
fprintf(stderr, "pthread_rwlock_unlock error: %s\n", strerror(err));
exit(1);
}
printf("%s: first child releases write lock\n", gf_time());
return NULL;
}
void *thread2(void *arg)
{
int err;
/* 4second child */
sleep(3);
printf("%s: second child tries to obtain read lock\n", gf_time());
if ((err = pthread_rwlock_rdlock(&rwlock)) != 0) {
fprintf(stderr, "pthread_rwlock_rdlock error: %s\n", strerror(err));
exit(1);
}
printf("%s: second child obtains read lock\n", gf_time());
sleep(4);
if ((err = pthread_rwlock_unlock(&rwlock)) != 0) {
fprintf(stderr, "pthread_rwlock_unlock error: %s\n", strerror(err));
exit(1);
}
printf("%s: second child releases read lock\n", gf_time());
return NULL;
}
int main()
{
pthread_t tid1, tid2;
Pthread_rwlock_wrlock(&rwlock); /* parent read locks entire file */
printf("%s: parent has write lock\n", gf_time());
Pthread_create(&tid1, NULL, thread1, NULL);
Pthread_create(&tid2, NULL, thread2, NULL);
/* 4parent */
sleep(5);
Pthread_rwlock_unlock(&rwlock);
printf("%s: parent releases write lock\n", gf_time());
Pthread_join(tid1, NULL);
Pthread_join(tid2, NULL);
exit(0);
}
int main()
{
pthread_t tid1, tid2;
int err;
if ((err = pthread_rwlock_wrlock(&rwlock)) != 0) { /* parent read locks entire file */
fprintf(stderr, "pthread_rwlock_wrlock error: %s\n", strerror(err));
exit(1);
}
printf("%s: parent has write lock\n", gf_time());
if ((err = pthread_create(&tid1, NULL, thread1, NULL)) != 0) {
fprintf(stderr, "pthread_create error: %s\n", strerror(err));
exit(1);
}
if ((err = pthread_create(&tid2, NULL, thread2, NULL)) != 0) {
fprintf(stderr, "pthread_create error: %s\n", strerror(err));
exit(1);
}
/* 4parent */
sleep(5);
if ((err = pthread_rwlock_unlock(&rwlock)) != 0) {
fprintf(stderr, "pthread_rwlock_unlock error: %s\n", strerror(err));
exit(1);
}
printf("%s: parent releases write lock\n", gf_time());
if ((err = pthread_join(tid1, NULL)) != 0) {
fprintf(stderr, "pthread_join error: %s\n", strerror(err));
exit(1);
}
if ((err = pthread_join(tid2, NULL)) != 0) {
fprintf(stderr, "pthread_join error: %s\n", strerror(err));
exit(1);
}
exit(0);
}
void *child_thread(void *arg)
{
/* 4child */
int err;
if ((err = mypthread_rwlock_rdlock(&rwlock)) != 0) { /* this should work */
fprintf(stderr, "mypthread_rwlock_rdlock error: %s\n", strerror(err));
exit(1);
}
printf("%s: child has read lock\n", gf_time());
sleep(2);
if ((err = mypthread_rwlock_unlock(&rwlock)) != 0) {
fprintf(stderr, "mypthread_rwlock_unlock error: %s\n", strerror(err));
exit(1);
}
printf("%s: child releases read lock\n", gf_time());
if ((err = mypthread_rwlock_rdlock(&rwlock)) != 0) { /* this should work */
fprintf(stderr, "mypthread_rwlock_rdlock error: %s\n", strerror(err));
exit(1);
}
printf("%s: child has read lock\n", gf_time());
sleep(2);
return NULL;
}
void
str_cli(FILE *fp, int sockfd)
{
int maxfdp1, val, stdineof;
ssize_t n, nwritten;
fd_set rset, wset;
char to[MAXLINE], fr[MAXLINE];
char *toiptr, *tooptr, *friptr, *froptr;
val = Fcntl(sockfd, F_GETFL, 0);
Fcntl(sockfd, F_SETFL, val | O_NONBLOCK);
val = Fcntl(STDIN_FILENO, F_GETFL, 0);
Fcntl(STDIN_FILENO, F_SETFL, val | O_NONBLOCK);
val = Fcntl(STDOUT_FILENO, F_GETFL, 0);
Fcntl(STDOUT_FILENO, F_SETFL, val | O_NONBLOCK);
toiptr = tooptr = to; /* initialize buffer pointers */
friptr = froptr = fr;
stdineof = 0;
maxfdp1 = max(max(STDIN_FILENO, STDOUT_FILENO), sockfd) + 1;
for ( ; ; ) {
FD_ZERO(&rset);
FD_ZERO(&wset);
if (stdineof == 0 && toiptr < &to[MAXLINE])
FD_SET(STDIN_FILENO, &rset); /* read from stdin */
if (friptr < &fr[MAXLINE])
FD_SET(sockfd, &rset); /* read from socket */
if (tooptr != toiptr)
FD_SET(sockfd, &wset); /* data to write to socket */
if (froptr != friptr)
FD_SET(STDOUT_FILENO, &wset); /* data to write to stdout */
Select(maxfdp1, &rset, &wset, NULL, NULL);
/* end nonb1 */
/* include nonb2 */
if (FD_ISSET(STDIN_FILENO, &rset)) {
if ( (n = read(STDIN_FILENO, toiptr, &to[MAXLINE] - toiptr)) < 0) {
if (errno != EWOULDBLOCK)
err_sys("read error on stdin");
} else if (n == 0) {
#ifdef VOL2
fprintf(stderr, "%s: EOF on stdin\n", gf_time());
#endif
stdineof = 1; /* all done with stdin */
if (tooptr == toiptr)
Shutdown(sockfd, SHUT_WR);/* send FIN */
} else {
#ifdef VOL2
fprintf(stderr, "%s: read %d bytes from stdin\n", gf_time(), n);
#endif
toiptr += n; /* # just read */
FD_SET(sockfd, &wset); /* try and write to socket below */
}
}
if (FD_ISSET(sockfd, &rset)) {
if ( (n = read(sockfd, friptr, &fr[MAXLINE] - friptr)) < 0) {
if (errno != EWOULDBLOCK)
err_sys("read error on socket");
} else if (n == 0) {
#ifdef VOL2
fprintf(stderr, "%s: EOF on socket\n", gf_time());
#endif
if (stdineof)
return; /* normal termination */
else
err_quit("str_cli: server terminated prematurely");
} else {
#ifdef VOL2
fprintf(stderr, "%s: read %d bytes from socket\n",
gf_time(), n);
#endif
friptr += n; /* # just read */
FD_SET(STDOUT_FILENO, &wset); /* try and write below */
}
}
/* end nonb2 */
/* include nonb3 */
if (FD_ISSET(STDOUT_FILENO, &wset) && ( (n = friptr - froptr) > 0)) {
if ( (nwritten = write(STDOUT_FILENO, froptr, n)) < 0) {
if (errno != EWOULDBLOCK)
err_sys("write error to stdout");
} else {
#ifdef VOL2
fprintf(stderr, "%s: wrote %d bytes to stdout\n",
gf_time(), nwritten);
#endif
froptr += nwritten; /* # just written */
if (froptr == friptr)
froptr = friptr = fr; /* back to beginning of buffer */
}
}
if (FD_ISSET(sockfd, &wset) && ( (n = toiptr - tooptr) > 0)) {
if ( (nwritten = write(sockfd, tooptr, n)) < 0) {
if (errno != EWOULDBLOCK)
err_sys("write error to socket");
} else {
#ifdef VOL2
fprintf(stderr, "%s: wrote %d bytes to socket\n",
gf_time(), nwritten);
#endif
tooptr += nwritten; /* # just written */
if (tooptr == toiptr) {
toiptr = tooptr = to; /* back to beginning of buffer */
if (stdineof)
Shutdown(sockfd, SHUT_WR); /* send FIN */
}
}
}
}
}
void str_cli(FILE * fd, int sockfd)
{
int maxfdp1, val, stdineof;
ssize_t n, nwritten;
fd_set rset, wset;
char to[MAXLINE], fr[MAXLINE];
char *toiptr, *tooptr, *friptr, *froptr;
val = Fcntl(sockfd, F_GETFL, 0);
Fcntl(sockfd, F_SETFL, val | O_NONBLOCK);
val = Fcntl(STDIN_FILENO, F_GETFL, 0);
Fcntl(STDIN_FILENO, F_SETFL, val | O_NONBLOCK);
val = Fcntl(STDOUT_FILENO, F_GETFL, 0);
Fcntl(STDOUT_FILENO, F_SETFL, val | O_NONBLOCK);
toiptr = tooptr = &to[MAXLINE];
friptr = froptr = &fr[MAXLINE];
stdineof = 0;
maxfdp1 = max(max(STDIN_FILENO, STDOUT_FILENO), sockfd) + 1;
for(;;)
{
FD_ZERO(&rset);
FD_ZERO(&wset);
if(stdineof == 0 && toiptr < &to[MAXLINE])
FD_SET(STDIN_FILENO, &rset);
if( friptr < &fr[MAXLINE] )
FD_SET(STDOUT_FILENO, &rset);
if(toiptr != tooptr)
FD_SET(sockfd, &wset);
if(friptr != froptr)
FD_SET(STDOUT_FILENO, &wset);
Select(maxfdp1, &rset, &wset, NULL, NULL);
if (FD_ISSET(STDIN_FILENO, &rset))
{
if( (n = read(STDIN_FILENO, toiptr, &to[MAXLINE] - toiptr)) < 0)
{
if( errno != EWOULDBLOCK )
err_sys("read error on stdin");
}
else if(n == 0)
{
fprintf(stderr, "%s: EOF on stdin\n", gf_time());
stdineof = 1;
if (toiptr == tooptr)
Shutdown(sockfd, SHUT_WR);
}
else
{
fprintf(stderr, "%s: read %d bytes from stdin\n", gf_time(), n);
toiptr += n;
FD_SET(sockfd, &wset);
}
}
if(FD_ISSET(sockfd, &rset))
{
if( (n = read(STDOUT_FILENO, friptr, &fr[MAXLINE] - friptr)) < 0)
{
if( errno != EWOULDBLOCK )
err_sys("read error on socket");
}
else if(n == 0)
{
fprintf(stderr, "%s: EOF on stdin\n", gf_time());
if(stdineof)
return; /* normal termination */
else
err_quit("str_cli server terminated prematurely");
}
else
{
fprintf(stderr, "%s: read %d bytes from socket\n", gf_time(), n);
friptr += n;
FD_SET(STDOUT_FILENO, &wset);
}
}
if(FD_ISSET(STDOUT_FILENO, &wset) && ( n = (friptr - froptr)) > 0)
{
if( (nwritten= write(STDOUT_FILENO, froptr, n)) < 0)
{
if(errno != EWOULDBLOCK)
err_sys("write error to stdout");
}
else
{
fprintf(stderr, "%s: wrote %d bytes to stdout\n", gf_time(), nwritten);
froptr += n;
if(froptr == friptr)
froptr = friptr = fr;
}
}
if(FD_ISSET(sockfd, &wset) && ( n = (toiptr - tooptr)) > 0)
{
if( (nwritten= write(STDOUT_FILENO, froptr, n)) < 0)
{
if(errno != EWOULDBLOCK)
err_sys("write error to socket");
}
else
{
fprintf(stderr, "%s: wrote %d bytes to socket\n", gf_time(), nwritten);
tooptr += n;
if(tooptr == toiptr)
{
tooptr = toiptr = to;
if(stdineof)
Shutdown(sockfd, SHUT_WR);
}
}
}
}
}
